A process plant is a complex, multifaceted entity, a structured organization of physical elements, operated for economic and other criteria that are often industry-specific. A process plant has a number of different stakeholders who can affect and/or are affected by its operation. Critical to the operation of many process plants today is a process control system, which ensures that appropriate parameters are measured and actions taken, plant personnel are kept informed, abnormal situations are identified and addressed, and business processes are integrated. Automation and control systems are employed in diverse applications, such as refining and petrochemical plants, the petroleum and natural gas supply chain, pulp and paper manufacturing, electrical power generation, chemical production, food production, wastewater treatment, discrete product manufacturing, cable-laying ships, tunnel ventilation control, and mining operations.
In many process control applications the cost of running wires from nodes such as sensors, actuators and user interfaces to the process control system limits the number and location of such nodes initially deployed. Cost and difficulty of wiring installation may also limit the deployment of additional nodes in an already-functioning plant. The recent development of wireless communication technologies, such as Bluetooth, IEEE® 802.11, RFID and others, promises a solution to such wiring costs, but not without introducing new challenges to the reliability and security of a process control system.
The ambient environment of a process plant may interfere with or prevent wireless communication between a sensor, actuator or user interface location and the process control system, making it difficult to connect a wireless node. Individual messages may be lost, or changes to the physical plant or electrical environment may prevent communication where it was previously possible, resulting in unreliable communication.
One of the top priorities at an industrial facility is security. Perimeter security, access controls, and communication systems may be elements of a security system at an industrial facility.
Sensors in a security system may include cameras, access readers and motion sensors. However, the costs of installing cables and wires to such sensors for power and data communications are generally high. Such costs may serve as a disincentive to an industrial facility owner to operate an effective security monitoring and alarm system.
Some industrial facilities and other commercial facilities have miles of perimeter to monitor, and security cameras may be required every 100 to 200 feet along the perimeter. Thus, 25 to 50 security cameras, along with associated power and data cables and trenches in which to install the cables, may be required for every mile of facility perimeter.
Furthermore, monitoring such a multitude of cameras may require a complex monitoring system. Data from each sensor may be routed to a single control center for monitoring and alarm generation. Both human and equipment costs for such monitoring may be high. As a result, current security monitoring systems may have high installation costs and monitoring costs when used in an industrial facility. Furthermore, where implemented with wireless communication, the communication reliability of current security monitoring systems may be low.